win_update refactoring

I decided to invest in doing it right since this was a wanted feature. And since I discovered salt brings pywin32 with it, I was able to refactor the module and still have something that meets the contrib requirement of being a drop in place module. This made the file a lot shorter and easier to maintain, and no knowledge of visual basic required! I still need to do some more testing on it, but that will have to wait till tomorrow.

I may have been in a harry potter mood when I wrote it. I can change the variables to something boring if that is a problem. You have to entertain yourself when you program some how no?